Agreed! That is sweet. I might have to get me one myself.
Ok - he's human - can't perform miracles, and there will probably be some variation piece to piece, not to mention variations in our own measurements (I've been seeing this a lot on these 300+ kcd lights...), but he's pretty good at tweaking units that need tweaking. I'm dying to see this K40 now though - size does matter 
, but the smaller the better...
I still don’t think there is that much difference between the k40 and tn31 when both are prepared the same. I have also done some tests on this TN31 where it tested slightly lower and some slightly higher. I’m finding at this level, small things can make a big difference in results. Plus 10k is only 2% of max lux for a light of this caliber.
For an example lets look at a light with exactly 500k. If that number was obtained by testing at 15m, simply moving the light too close or too far by just the lights length itself - basically 200mm - it would skew the results by about 13k. Just the lights length isn’t much when were talking 15m. And it gets more critical the closer you are. If you test the light at 5m, and again goof on your test distance by the 200mm, that would throw your reading off by 40k.
So what I saying is on lights in this range, take the max lux number with a grain of salt. Even as much testing as I do, I admit I could goof 10cm here or there. I try to be as consistant as possible, but I’m only human.
You see it’s the high lux level that were up to now that is making measurements and other things so critical. For example, a good old traditional thrower like my SR51. Great light that consistently gets about 52K. Now using it for example, same scenario testing at 15m, if you goof by the same 200mm - this case your only talking about only 1.4K, or a basically a reading of 50.6K vs the proper 52K. Pretty minor difference really. It’s about the same percentage of difference, but when numbers are lower it puts it into a normal error perspective.
So guys don’t get TOO worked up about one light doing 460k and another doing 490K, etc. That difference could be LED bins, not fully charged cell, or mostly likely a slight variance in testing methods or equipment.
Basically any K40 or TN31 driven at 6.5A along with a dedomed XML2 U2, along with the other proper mods, is going to kick serious butt. Big time.
im going to order 6 panasonic PDs to test and see if they make a diff
Did that, no difference. I've had 3 6.5A TN31's that I've been testing, and went through a whole myriad of cell assortments. Basically, no difference, but of course only on the 1st minute or 2. No doubt you will get differences as the cells drop, like in a few minutes, but initial tests showed no difference in KP 3400's, Pana PD's, Samsung 20R's, Samsung 20Q's, SONY 30A, etc.
I believe it's a quality buck driver, so not much dependence on cells - actually I measured 3.5-3.7A at the carrier, so each cell is pulling that amount of amps so it's well within the range of Panasonic based KP's for example.
FWIW the TN31mb has greater relative throw when you equalize for differences in luminous flux.
I never seriously considered a TN31mb but not sure I can live without one of these… even if it goes up in a wisp of smoke in a few weeks 
JUST FYI:
360kcd is still pretty great. Because of the inverse law there are diminishing returns once you get up into the plus 250k range (subjective).
50kcd = 447 meters (+447 meter gain)
100kcd = 632 meters (+185 meter)
150kcd = 775 meters (+143 gain)
200kcd = 894 meters (+119 gain)
250kcd = 1000 meters (+106 gain)
300kcd = 1095 meters (+95 gain)
350kcd = 1183 meters (+88 gain)
400kcd = 1265 meters (+82 gain)
450kcd = 1342 meters (+77 gain)
500kcd = 1414 meters (+72 gain)
550kcd = 1483 meters (+69 gain)
With every increase of 50kcd, it decreases significantly. You need 4x the lux to throw twice the distance.
Achieving 500kcd is a great feat, and achieving 350kcd is still a great feat. They both throw close to the same distance.
Slewflash,
That’s a great comparison chart so we can see the difference. Thanks so much for taking the time to post that.
Vinh tells me he got my K40 today and he is already done with it and going to ship it back. He’s very quick. I can’t wait to compare this K40 to the TN31 he did.
He got it today and it’s already done? Wow that’s fast. I mailed mine to him on Monday and he just got it today 
I would be interested to see a de-domed Niwalker BK-FA01 modded to 6.5A tested alongside these. That light has a stock lux rating of 142kcd. They are really nice lights too. I’ve had the BK-FA02 for about a month and I honestly think the build quality is better than the TN31.
Yeah, that is pretty cool to break it down like that Slewflash. Most know how to calculate it ok, but the chart you made gives a nice comparison of all the numbers. Thanks!
I’m not surprised, I’ve read extensively about the Niwalker BK-FA01 and it looks like a really great stock thrower.
And no worries about the chart. I’ve got the formula so ingrained in my head that it was just a 2 minute job with a calculator.
De-doming would get you to about 300 kcd, so the rest would be mostly boosting amps, so 450-500 sounds feasible, all depends on it's 'modability'.
Wonder bout it - runtime is just under 2 hrs for 4 cells, so they could be decent amps already. Definitiely looks better than a TN31 from the pics.
jmpaul,
what about level one and two, i was hoping for a low low. approx how many lumens?
as for the batteries, a few members here recommended me these batteries for my modded k40 and btu shocker.
http://www.fasttech.com/products/1420/10001901/1143802-sanyo-ur18650f-18650-2600mah-protected-rechargeabl
rdrfronty,
since you said your doing throwers and a couple flooders, i wouldnt mind seeing the srk and all the srk lookalikes up in the mix as well.
the kung, terminator, warrior or whatevers you got that.
For certain we will have a King, Kung, and Terminator in the mix. They arn’t too throwy (terminator is decent) but they all have enough power we thought it justified including them. I have a M6 ordered, but with its slow progress, looks like its not coming in time.
rdrfronty, could ta possibly include xintd v4 and thanks again.
XinTd V4 C8 correct? Sure, its a nice light and should reach the 300m target fine. I’ll have brother bring it along for the shots.
could you bring along an sk68? 
ok - good to know - i can use the pds in the super shocker though
low low is very nice! probably about 10 lumens - its still throwey though… good for use around a dark house!